Browse Prior Art Database

Core Memory Drive

IP.com Disclosure Number: IPCOM000097053D
Original Publication Date: 1962-Apr-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 26K

Publishing Venue

IBM

Related People

Levi, MW: AUTHOR

Abstract

Operational speed of magnetic core memories is limited by the time required to drive a core from one state to another to read and write information in it. This drive system increases operational speed by shortening readout and write-in times. If short duration, high amplitude read and write pulses are employed, the core can be operated entirely upon minor loops, away from saturation at all times. By entirely preventing saturation, significant increases in operating speed are realized.

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Core Memory Drive

Operational speed of magnetic core memories is limited by the time required to drive a core from one state to another to read and write information in it. This drive system increases operational speed by shortening readout and write-in times. If short duration, high amplitude read and write pulses are employed, the core can be operated entirely upon minor loops, away from saturation at all times. By entirely preventing saturation, significant increases in operating speed are realized.

The drive system is used in a two-dimensional or word-organized array. Read and write drive pulses of substantially equal amplitude and duration are employed. Both are above the switching threshold of the core, but of insufficient duration to drive it to saturation. During writein, an inhibiting pulse is applied on the bit windings of cores in which a 0 is to be stored. This reduces the net write drive and causes the core to be switched to a lower state than if the write drive is applied alone. To write a 1, no bit drive is applied.

The readout pulse drives the core from the 1 or 0 state to the read state to produce a detectable output. Although cores storing different information initially reside in different states, the non-saturating read drive leaves them at about the same point. There is no appreciable walking.

The hysteresis diagram shows that substantial 0 signals are induced with this system. While a sufficient amplitude ratio is maintained between 1's and...